This invention relates to a combination landfill leachate collection and leachate leak detection system.
Government regulations have made it a requirement for the industry to construct landfills for waste disposal to protect natural ground water resources from contamination by wastes. For example, the Environmental Protection Agency (EPA) requires landfills to be constructed with liners below the waste landfill as barriers against the penetration of waste to the ground water.
Prior to environmental regulations, the general practice of the industry was to provide an unlined excavation or a single lined excavation. However, because of recent environmental concerns and an increasing demand for the protection of ground water resources, stricter environmental regulations are being enforced. For example, the EPA has now made it a requirement for landfills to contain at least two liners separating the waste in the landfill from the natural soil. The EPA requires that a double liner landfill system be designed, constructed and operated to protect human health and the environment. In addition, the EPA requires a leachate collection and removal system in combination with a leachate leak detection system incorporated into the construction of a landfill. While the EPA has published general guidelines for constructing a double liner landfill system, the guidelines provide no specifics on the final construction of a landfill system. Much of the detail construction of the double liner landfill system is left up to the innovation of the owner of such landfill.
The EPA guidelines disclose that a sump system for landfills can be used, but do not describe a sump system which provides support for the necessary pumps, piping or structures for personnel access.
In some landfill installations it is known to use a small leak detection pipe extending down the slope of a landfill cell levee between two liners. In this type of system it is very difficult to determine the level of leachate leakage and to pump the leachate out of the cell.
It is desired to provide a novel and dependable landfill system to comply with EPA requirements. More specifically, it is desired to provide a landfill system which utilizes at least two sumps and which:
1. is capable of detecting, collecting and removing leachate in the landfill through the life of the landfill;
2. is easy to construct and maintain for the life of the landfill; 3. is chemically resistant to wastes or leachate present in the landfill;
4. is structurally strong enough to support sump pumps and piping;
5. is capable of withstanding the stresses and disturbances from overlying wastes and operating practices;
6. permits knowledge of leachate levels in the sumps;
7. allows easy sampling and withdrawal of leachate from the sumps;
8. provides maximum protection against leakage around the sumps; and
9. is acceptable to governmental regulatory agencies.